Engine frame



J. PAVLECKA ENGINE FRAME May 10, 1938.

Filed Aug. 10, 1956 2 Sheets-Sheet 1 VENTORI y 1938. J. PAVLECKA2,117,118

' ENGINE FRAME Fi1ed Aug. 10, 1936 2 Sheets-Sheet 2 NT OR:

Patented May 10, 1938 UNITED STATES PATENT OFFICE My present invention,first disclosed in my co-pending application .Ser. No. 50,552, relatesto a new frame for internal combustion engines,

particularly those disclosed in my Patent No.

.One object of my invention is to devise a simple but rigid structurefor mounting the crankshafts and the cylinders and providing a coolingjacket for the latter, in engines wherein a numher of cranks andcylinders are arranged in coplanar sets. I

A further object of my invention is to provide rigid supporting means inthe form of transverse bulkheads for the crankshafts in amultiplecrankshaft engine, and to incorporate these bulkheads in theengine frame in such a manner that forces on the crankshafts will opposeone another in the bulkheads without affecting other -members of theframe and engine. An important object of my invention is to devise ,asupporting structure for the cylinders in an engine having a number ofco-planar transverse cylinder sets, and to utilize this structure as acooling jacket, preferably in conjunction with an inner induction duct.

The ultimate object of my present invention is to present a frame foramultiple-crankshaft engine which will be light in weight and inexpensiveby virtue of being fabricated mostly of commercial forms of steel, suchas sheet metal and tubing.

These and other valuable objectives accomplished through my inventionwill now'be described on. a number of embodiments as illustrated in thedrawings accompanying this specification and forming an integral partthereof.

In the drawings,

I Fig. l is a perspective view of the new frame structure as appliedtoan engine embodying three co-planar cylinders in triangular formationin one plane and in any number of like planes side by side, as disclosedin my application Ser. No. 699,192; certain of the parts in this vieware f agmented in order to show others behind them to better advantage;

Fig. 2 is atransverse cross-section through an engine composed of threecranks and three cylinders in one plane. and in any numberof like planesside by side,.the cylinders being in star formation between the cranks;this section is taken immediately adjacent one of the transversebulkheads;

Fig. 3 is a transverse cross-section through an engine having four powerunits and four cranks in one plane, and in any number of like planesside by sideithis section beingtaken immediately in front of one of thebulkheads that support the four crankshafts;

Fig. 4 is a transverse cross-section through an engine embodyingtwocranks and one cylinder 5 between them in any one plane, the sectionbeing taken at one of the transverse bulkheads;

Fig. 5 represents a transverse cross-section through the cylinders in anengine frame em-' bodying three-cylinder co-planar units such as 10 inthe frame of Fig. 1;

Fig. 6 is a cross-section taken through the intake port I 5 and thecylinder in the plane indicated by 15-15 in Fig. 5, and

Fig. '7 is a cross-section taken in the plane 15 lfl'l4 in Fig. 5through the exhaust port 24 and the cylinder therein. y

Referring first jointly to all the figures in the drawings, my inventionrepresented therein manifests itself by certain characteristic parts and20 features that are the same regardless of the type and size of engine,and that include, among others, anumber of transverse bulkheads forsupporting the crankshafts, and one cylinder or a number of cylinders ina co-planar set disposed alongside each bulkhead, the cylinder orcylinders being open at both ends; both the bulkheads and the cylindersare held together in proper relation and in unity .by a number oflongitudinal deck plates or decks. These primary ele- 30 ments of theframethe bulkheads, the cylinders and the deck plates-constitute therigid skeleton that is intended to resist all the stresses within theengine, and about which the rest of the frame and the engine isassembled. 35 Connecting the edges of the deck plates is a number ofintervening panels that jointly with the deck plates form a coolingfluid jacket for the cylinders. Centrally through the bulkheads and thecylinder sets in the engines of Figs. 1, 3 40 and 5 extends a tubularinduction duct which supplies the cylinders with scavenging air and setof three cylinders I, 2 and I3 having the axes thereof intersect oneanother in triangular formation; only cylinders l and 2 are visible inFig. 1. The cylinders are open at both ends and contact one another.Each of the cylinders I 2, and 13 comprises two opposed pistons 66 and61 which are 'operatively journalled by means of the plain straightconnecting rods 68 and the forked rods 63, respectively, to two of thethree crankshafts ill to 12; these crankshafts are mounted rotatably inthe bulkheads 3 and 3' in juxtaposition .to the open ends of thecylinders. The twin pistons 63 and 61 in each cylinder reciprocate ingenerally opposite directions and at the end of their respective strokesuncover apertures communicating with the intake port l5 that surroundsthe cylinder near one end and the exhaust port 24 that surrounds thecylinder near the other end thereof.

The transverse bulkheads 3 and 3' are disposed alongside of the cylindersets and are of a generally three-cornered shape, the three extremitiesproviding seats I, 8, and 9 for crankshaft bearings, pads 60 for thebearing caps 28, and tapp d holes 59 for the bearing cap studs or boltswith nuts l0 thereon.

In the particular' embodiment as shown, the bulkheads 3 are fabricatedeach of two axially spaced web plates 4 and 5, both substantially alike,and the three bearing bases 6, the latter being cast or forged, machinedto the width between the web plates 4 and 5, and joined, as by weldingor brazing to the plates all along their edges. This constructionproduces hollow bulkheads all the way up to the bearing seats I, 8, and9, which feature is taken advantage of in my application Ser. No. 50,552above mentioned for cooling the crankshaft bearings.

For purposes disclosed presently, the bulkheads 3 are furthercharacterized in that they are provided, near their three extremities,at the proper angle, with seating shoulders, which shoulders appear asrecesses l6 and I! on the web plates case spaces.

on the bulkhead shoulders as formed by the web 4 and 5, and as lugs l8on the bearing heads 6, these lugs being at the end of side walls on thebases extending along the edges of the web plates 4 and 5 down to therecesses l6 and I1 and having a profile conforming thereto.

Extending lengthwise of the engine frame at proper angular spacing andinclination are the.

three deck plates ll, 52, and 13; these plates are slabs of steel thathave cut out in them rectangular openings to allow the bulkheads 3, andoval openings and to allow the ends of the cylinders I, 2 and 13 toprotrude through them into the crank- The decks ll, 82 and i3 are seatedplates at I 6 and I! and the bearing bases at la, in which manner theyare located correctly on the assembly and then joined, as by fusion, toboth the bulkheads 3 and the cylinders i, 2 and 13 all around theircontact therewith, thus becoming an integral part of the frame.

Considering now the secondary members of the frame structure, theseinclude, first, the induction duct H which is a tubular member extendingcentrally through the engine frame from one end to the other, andcomprises a number of ports l5 that branch ofito individual cylindersfor feeding air thereinto. preferably of sheet metal and has across-section characterized by three lobes fitting into the anglesbetween the cylinders, their curvilinear contour so obtained beingdevised to withstand de formation due to internal air pressu o this Theduct I4 is madev same end, the duct I4 is embraced by the .web plates 4and 5 of the bulkheads 3 as it passes through them, and is joined, as byfusion, to these plates as it is joined to the cylinders at and aroundthe ports l5. It may be observed that the induction duct l4 provides anatural centering back-bone in alining the bulkheads 3, and through thempositioning the deck plates II to I3, and through them in turn locatingthe cylinders I and 2 and the third one out of view.

Spanning the gaps between the edges of the deck plates II to 13, andforming a box-like polygonal casing therewith, are the side panels I3,20, and 2 I. These panels are made of a relatively thin sheet materialand are likewise joined, prefably by welding and brazing to the deckplates to form a leak-proof cooling fiuidcontainer therewith, while theinduction duct l4 in the interior provides the inner walls of thiscontainer, and by displacing a large amount of the cooling fluid reducesthe weight of the engine.

The exhaust ports 24 extend from the cylinders outwardly through thecooling fluid container and terminate with the flange 25 in the sidepanels l9 to 2| and are Joined by fusion all around 'to these panels.

The structure disclosed hereinabove completes the engine frame as aself-contained water-tight unit in which each member is specialized andconstructed for a certain function, and integrated by fusion with theother members into a structurally firm and functionally effectivestructure.

To complete the frame, crankcases 22, 23 and crankcases, due to theirvery deep section, provide substantial reinforcing members for thedeckplates against warping and weaving due to unbalanced stresses inthebulkheads, and in that respect constitute essential, although ofnecessity not integral, members of the engine frame of my invention.

The frame of the engine of Fig. 2 is distinguished by the samemembers'and features of construction and assembly as the frame of Fig.1; the difference resides in the type of engine, which comprises anumber of sets of three cylinders each, similarly as the engine of Fig.1, but the cylinders 29, 30 and 3| are arranged radially to a commoncombustion chamber, two of the cylinders, 30 and 3!, being provided withintake ports l5, and the third cylinder 29 with the exhaust port 24'.Three deck plates ll, i2 and I3, supported by a number of bulkheads 6iand in turn supporting the aforementioned cylinders, provide the --basicelements in the frame, while side panels i9, 20' and 56, and crankcases22. 23 and 35 complete the assembly; the difference in comparison withFig. 1 concerns mainly the absence of a central induction duct forobvious lack of room.

The bulkheads 6| are characterized again by the seating shoulders l6 andIT for locating and carrying the deck plates II to l3; three crankshafts32, 33 and 34 are mounted rotatably in the extremities of the bulkheadsunder the bearing caps 23.

Fig. 3 presents yet another embodiment of y invention, againcharacterized by the same component members and principles oftheirspecialization as to function and integration into a unit as the frameof Fig. 1, the difference being only in the number'of cylinders or powerunits in each set; in this instance there are four power units 45, 46,41 and 48, and four cranks ll, l2, l3 and 44 pertaining to as manycrankshafts, in one plane, the power units being preferably bentinwardly for reasons of timing of the cranks and of the pistons therein;as disclosed in my aforementioned application Patent No. 2,085,270. Thedifference in comparison with Fig. 1 resides merely in the number ofduplicate-members employed due to the "greater number of cylinders andcranks.

The bulkheads 62 resolve themselves into'four extremities that projectthrough the deck plates 31, 38, 39 and 40, and support the fourcrankshafts H to M in parallel relation; the bulkheads 62 aredistinguished by the same manner of construction of sheet metal webplates and solid bearing bases, both jointly giving rise to seatingshoulders I6" and H" for the deck plates,.as'that of the bulkheads ofFig. 1. Four side panels 52 complete the exterior of the. cooling fluidcontainer, while the four-lobed induction duct 63 provides an interiorwall for the container by occupying the core space within the cylindersets and between them;' furthermore,

the duct 63 carries the bulkheads 62 and is, in

turn, greatly reinforced thereby. Intake ports l5" communicate betweenand are joined, as by fusion, to the duct 63 and the cylinders or powerunits 45 to 48, and exhaust ports 24" extend between the cylinders andthe exterior of the engine through panels 52-. i

The adaptability of the structure of my invention to frames for alltypes of engines is further evidenced in Fig. 4, wherein an enginehaving but one cylinder t!) between two cranks 51 and 58, all in oneplane and in any number of like planes side by side, is shown. Thebulkhead 55, one on each side of each cylinder jil, is shown as beingcast or forged in one piece instead of being fabricated of webs andbearing bases, but

- otherwise it is characterized by the fact that itextends clear throughopenings in the engine frame between the crankshafts 51 and 58, and

by the same locating and seating shoulders l6"" and fl'l'" at eachextremity for the deck plates 64 and 65 to rest on, as the compositebulkheads in previous figures. Side panels 53 and 54, with exhaust andintake ports l5"' and 24" passing through them, form, jointly with thedeck plates 56 and 65, a cooling jacket for the cylinder or cylindersd9, similarly as in the preceding embodiments, and the crankcases 50 and5| provide substantial reinforcing members for the deck plates 64 and 65against stresses not equalized in the bulkheads 55.

I claim: 1. In a box-like engine frame having longitudinally andoppositely spaced openings in the sides thereof,v a number of unitarytransverse bulkheads for mounting a number of crankshafts in paralleland opposed relation about said frame, said bulkheads comprising each acentral web portion encompassed within said frame sides and a number ofintegral outer bearing bases inserted in, secured to andprotrudingexteriorly from said openings in said sides.

2. In a box-like engine frame having longitudinally and angul'arlyspaced openings in the sides thereof, a number of unitary transversebulkheads for mounting a number of crankshafts in parallel and angularlydisposed relation about said frame, said bulkheads comprising each acentral web portion encompassed within said bases inserted in, securedto and protruding exteriorly from said apertures in said frame.-

4. In a box-like engine frame supporting a set or sets of co-planar openend cylinders and providing a cooling fluid jacket therefor, said jackethaving apertures adjacent said cylinder ends, unitary transversebulkheads having each a central web portion and a number of integralouter bearing bases for mounting a number of parallel crankshafts injuxtaposition to said cylinder ends, said web portion of said bulkheadsbeing contained for the most part' within said cooling jacket with saidbearing bases'inserted in, secured to and protruding exteriorly fromsaid apertures therein.

5. In a box-like engine frame having walls with longitudinally spacedapertures therein, a number of unitary transverse bulkheads comprisingeach a web portion encompassed for the most part within said frame and anumber of outer bearing bases integral with said web portion, eachbearing, base having shoulders abutting the underside of said framewalls and beyond said shoulders projecting exteriorly through saidapertures therein and forming a crankshaft bearing seat away from saidshoulders.

6. In a box-like engine frame having walls with longitudinally spacedapertures therein, a number of unitary transverse bulkheads comprisingeach a web portion encompassed for the most part within said frame wallsand a number of outer bearing bases integral with said web portion, eachbearing base having a crankshaft bearing seat and lateral bearing padsfor bearing caps, and having flanges extending from said pads downwardlyand forming seating shoulders underneath said frame walls forpositioning said bulkheads in and securing them to said frame.

7,. In a box-like engine frame having walls with longitudinally spacedapertures therein, a number of unitary transverse bulkheads for mountinga number of crankshafts alongside of said frame, said bulkheadscomprising two central spaced web plates encompassed for the most partwithin said frame walls and therefrom projecting outwardly through saidapertures therein, and bearing bases for said crankshafts held by andbetween said projecting portions of said web plates and between themextending downwardly to the inside of said frame and therein formingshoulders against said walls thereof for locating and securing saidbulkheads in place.

8. An engine frame supporting a number of open end cylinders disposedtransversely between a number of parallel crankshafts, bulkheads hav-.

ing a center portion alongside of said cylinders and integral outerbearing bases thereon for mounting said crankshafts rotatably, and anumber of deck plates extending along said crank shafts and havingopenings therein for accommodating and supporting said cylinder ends,and

longitudinal deck plates extending along said crankshafts and havingcurvilinear openings therein for said cylinder ends, and havingrectangular openings adjacent said cylinder openings, I

and transverse unitary bulkheads having a central portion alongside ofsaid cylinders between said deck plates and having a number of integralbearing bases for mounting said crankshafts rotatably, said bearingbases being projected through said rectangular openings in said deckplates, and means for securing said bulkheads to said deckplates aroundsaid openings.

10. An engine frame comprising, a. number of angularly spacedlongitudinal deck plates, a number of cylinders disposed transverselybetween said deck plates and projected therethrough, unitary bulkheadsdisposed alpngslde of said cylinders and consisting each of two spacedweb plates constituting the center portion of said bulkheads betweensaid deck plates and having outer extremities projecting through saiddeck plates, and crankshaft bearing bases in said extremities partiallybetween said web plates, said bearing base's bordering along the edgesof said web plates down to the underside of said deck plates and formingseating shoulders thereat. f

11. An engine frame comprising, a number of cylinders open at both endsand disposed transversely between a number of parallel crankshafts,

- bulkheads having a center portion alongside of said cylinders andintegral outer bearing bases therearound for mounting said crankshaftsrotatably, a number of deck plates extending along said crankshafts andhaving openings therein for accommodating both said open ends of saidcylinders and said bases of said bulkheads, and intervening panelsextending between said deck plates and jointly therewith surroundingsaid said open ends of said cylinders, crankcases abutting said deckplates and being secured thereto, and a number of intervening panelsbetween said deck plates forming a cooling fluid jacket jointlytherewith for said cylinders and with said crankcases defining theexterior of the engine.

13. An engine frame comprising, a number of longitudinal deck plates, anumber of intervening panels secured to said deck plates and jointlytherewith forming a cooling fluid jacket, a number of cylinders disposedin said jacket between said deck plates and projected through said deckplates with open ends, and a number of unitary bulkheads having acentral webbed portion within said cooling jacket alongside of saidcylinders and projecting through said deck plates outwardly and carryingbearing bases above said deck" plates, said bulkheads being located inand secured to said deck plates through the instrumentality of saidbearing bases there- 14. In an engine frame, a number of cylindershaving both ends open and being arranged in co-planar polygonal sets,bulkheads alongside of said cylinder sets having a central webbed poringbases thereon, a cooling fluid container surrounding said cylinder setsbetween said open ends thereof, and a tubular induction duct extendingcentrally through said cylinder sets and f tion and a number of integralcrankshaft bearportion transversely of said deck plates and integralouter bearing bases above said plates for mounting crankshaftsrotatably, a number of cylinders disposed in co-planar polygonal setsbetween said deck plates alongside of saidbulkheads, and an inductionduct for said cylinders co-planar polygonal sets, bulkheads alongside ofsaid cylinder sets having a webbed central portion and a number ofintegral crankshaft bearing bases therearound, a cooling fluid containersurrounding said cylinders between said open ends thereof, and a tubularinduction duct for supplying said cylinders with scavenging airextending centrally through said cylinder sets and through saidbulkheads and forming a supporting means therefor and having intakeports thereon branching of! to said cylinders, said duct havingcurvilinear walls in transverse cross section forming a number of lobesfitting into the angles between the cylinders in the sets for resistanceto deformation due to internal pressure.

17. An engine framecomprising, a central tubular induction duct, unitarytransverse bulkheads embracing said duct and having each a number ofintegral outer crankshaft bearing bases, 'a number of cylinders open atboth ends and arranged in co-planar sets alongside of said bulkheadsaround said induction duct, intake ports connecting said duct with saidcylinders, a number of deck plates having apertures therein foraccommodating said bearing bases of said bulkheads and having otherapertures for said open ends of said cylinders and being secured to bothall around their line of contact therewith, intervening panelsbetweensaid deck plates secured thereto and jointly therewith formingthe exterior of a cooling fluid container for said cylinder sets withsaid induction duct providing the interior of said container, exhaustports extending between said cylinders and said panels, and crankcasesabutting said deck panels and being secured as reinforcing membersdetachably I thereto.

18. An engine frame mounting three parallel crankshafts comprising,three decks extending along said crankshafts, a number of sets of threecylinders each between said crankshafts, the cylinders in each sethaving intersecting axes and open ends projecting through said decks, anumber of unitary bulkheads consisting each of a central web portionbetween said decks alongside of said cylinder sets and three bearingbases integral with said'web portion and projecting through said decksfor supporting said crankshafts rotatably thereabove, a crankcaseabutting each of said decks, intervening panels between said decksforming jointly therewith a cooling fluid container for said cylindersets, and intake and exhaust ports projecting from said cylindersthrough said fluid container.

19. An engine frame mounting three parallel crankshafts comprising,three decks extending along said crankshafts, a number of sets of threecylinders each defining triangular formations between said crankshaftsand having open ends projecting through said decks, a number of unitarybulkheads consisting each of a central web portion between said decksalongside of said cylinder sets and three bearing bases outside of saiddecks for supporting said crankshafts rotatably, a crankcase abuttingeach of said decks, intervening panels between said decks formingjointly said bulkheads and said cylinder sets and forming an interiorwall of said fluid container, intake ports extending between saidinduction duct and said cylinders, and exhaust ports extending betweensaid cylinders and said panels.'

20. An engine frame mounting four parallel crankshaits comprising, fourdecks extending along said crankshafts, a number of setsof fourcylinders each defining a polygonal pattern between said crankshafts andhaving open ends projecting through said decks, a number of unitarybulkheads consisting each of a central web portion between said decksalongside of said cylvening panels between said decks forming jointlytherewith an exterior wall of a cooling fluid con-

